Sweet steviol glycoside compounds are present in small concentrations and can be extracted from plant materials, particularly the leaves of the Stevia rebaudiana Bertoni plant. In a crude stevia extract these compounds typically are found to include stevioside, steviolbioside, several Rebaudiosides, including Rebaudioside A, Rebaudioside B, Rebaudioside C, Rebaudioside D, and Rebaudioside E, and Dulcoside compounds. For convenience, the Rebaudiosides may be referred to here as Reb A, Reb B, Reb C, etc.
Of the rebaudiosides, Reb A is commonly used as sweetener in beverage applications, but has off-taste issues. Reb D has a better sugar character and more desirable taste than Reb A, but Reb D is difficult to use in beverage products because of its low solubility in water at room temperature. For instance, Reb D needs to be heated to near boiling water temperature for 2 hours in order to achieve complete dissolution. See US Publication 20110189360, for example. In room temperature, at most about 500 ppm can be solubilized in water.
Reb D has a sweetness potency similar to that of Reb A (about 200 times sweeter than sugar). As such, with about 500 ppm water solubility, Reb D can provide decent sweetness to the beverage. However, this solubility poses a problem for making a carbonated soft drink employing Reb D as a primary sweetener.
Traditional processes for making carbonated soft drinks (CSDs) require a 6 folds concentration of ingredients in a concentrate or syrup. This syrup is then diluted by 5 folds of water and injected with CO2 to form the CSD (cola, lemon-lime, etc.). This works fine if all syrup ingredients are soluble in water to the extent of 6 folds of the level in the finished beverage. In other word, if Reb D is the primary sweetener of a CSD, its water solubility needs to be 3000 ppm if the finished beverage is formulated with 500 ppm of Reb D. US Publication 20110189360 teaches heating to near boiling, but this is not practical as the beverage bottler does not like to conduct such high temperature heating. Moreover, upon cooling Reb D may precipitate down from the super-saturated solution within a few hours.
Accordingly, it is an object of some aspects of the present invention to provide a method of making a diet CSD sweetened with low solubility sweeteners such as Reb D. Additional objects and advantages of all or certain embodiments of the systems and methods disclosed here will be apparent to those skilled in the art given the benefit of the following disclosure and discussion of certain exemplary embodiments.